1. Field of the Invention
The present invention relates to memory cards and to communication methods between memory cards and host units. In particular, the present invention relates to bridge implementations between memory cards and host units so as to realize high throughput of data.
2. Background of the Related Art
Memory cards are widely used nowadays for the purpose of storing several kinds of data such as video data, audio data, image data, text data and the like. Flash memory cards, for example, are solid state electronic flash memory data storage devices capable of storing digital contents and they are mainly used with digital cameras, personal computers, music players, video games consoles, laptops, and other electronic devices. They offer high rerecord ability, power free storage and, especially in recent times, they are characterized by very small dimensions.
Moreover, one of the most recent uses of memory cards is with mobile phones and similar small screen devices such as GPS, PDA, and smart phones that allows the reception and transmission of data in a wireless scenario. GPS, PDA, smart phones, and mobile phones use memory cards and smart cards. In particular, smart cards for mobile devices allow for support of reception and transmission of broadcasted signals and of broadcasted encrypted signals. Common examples of smart cards are the subscriber identity module cards typically used for mobile devices.
An example of a secure MMC (multi-media card) standard smart card with multi-application operation capability is disclosed in EP1927939A1. In particular, the system disclosed in this document allows starting, running and querying multiple applications in parallel and concurrently in a card connected to a host through a MMC bus. In particular, one of the main problems concerning the employment of memory cards in a wireless scenario together with devices adapted to support reception and transmission of broadcasted signals, such as video channels, radio channels and the like, relates to the speed at which the data can be transmitted from and to the memory card. In particular, the speed of data transmission from and to the memory card is connected with two main problems.
First of all, low speed data transmission implies very poor quality of the signal as output to the user. In particular, the quality at which the data content is displayed strongly depends on the speed at which the data can be transmitted from and to the memory card. Low speed transmission may, for instance, result in very slow reproduction of video and/or audio data.
A second problem concerning the data transfer speed relates to the fact that while occupied with the data transfer, the processor of the system is in a busy state and cannot process other kinds of commands. Accordingly, if the data transfer speed is too low, the processor is occupied for a long time and the entire device is overcharged by operations. Accordingly, the processor cannot perform other tasks and the device is slowed down.
Given these problems with the existing technology, it would be advantageous to provide a system which allows for the operation of memory cards in a wireless scenario in such a way so as to guarantee high quality data output and, at the same time, low workload for the processor of the system.